The invention consists of a clamping device for a grinding disc or, more specifically, a grinding ring. The device includes a clamping flange and a support flange which has positioned along the length of its supporting portion several radially protruding outer wedges whih are assigned to corresponding inner grooves within the borehole of the grinding ring. The present clamping device allows the balancing and detachable fastening of a grinding ring on a driving shaft so that it excludes distorting and damaging of the grinding ring. For this purpose the supporting portion of a support flange of the driving shaft and the grinding ring are provided with interacting guiding means, namely the aforementioned radially protruding outer wedges and cooperating inner grooves in the inner surface of the bore hole of the grinding ring.
Usually grinding rings have circular boreholes, and accordingly the support pivots of the clamping flange usually also have circular cross sections. Because of the high number of revolutions at which grinding rings are spinning, eccentricities in the grinding ring bearings produce dangerously high mass energy. When clamping a grinding ring, it is therefore important to avoid imbalance, i.e. exact centering is important. The known grinding rings therefore keep the play between the grinding ring borehole and the support pivot as small as possible. This avoids imbalance, however, it is accompanied by the disadvantage, that mounting a grinding ring on a support pivot is very difficult. Because of the tight play, the grinding ring deforms easily during mounting, and then, if possible at all, it takes much dexterity to undo the deformation without damaging the grinding ring during loosening it and trying again to slip it on. Many accidents during grinding are caused by practically invisible defects of the grinding ring, which occur during clamping in the clamping device.
Up to now, grinding disks for utilization on grinding machines have been slipped on a mandrel, respectively a supporting portion of the support flange, and have been fixed in their final position by means of, for instance, a clamping flange (U.S. Pat. No. 2,497,217). The main disadvantage of this known grinding ring clamping device consists therein, that it is difficult to mount the grinding disk on the support, because of its low tolerance. This is especially so, when the grinding disk is mounted slightly inclined on the support, which leads to deformation, whereafter subsequent mounting becomes impossible, and which furthermore leads to damage through distortion in the borehole of the grinding disk. This in turn leads to a further disadvantage of resulting in unbalanced spinning of the grinding disk.
There is another known clamping device for a grinding ring having the above mentioned disadvantages (FR-PS No. 445,807), where by means of wedges on the support flange and grooves in the grinding ring, supposedly a connection between these parts is made, which avoids bursting of the grinding ring.